foojay — a place for friends of OpenJDK

Virtual Foojay JUG Tour

To celebrate the OpenJDK and Foojay.io as a community platform for its users, we’re kicking off the Virtual Foojay JUG Tour. Ari Waller, JFrog’s Event Manager, well known to many JUGs, now wears a second hat—that of Foojay Event Manager. During March and April, contributors to Foojay will be making a whistle stop tour through as many JUGs as possible, via their virtual meetups!

At each stop of the tour, there’ll be a brief introduction to Foojay.io followed by a session of 30 minutes on a topic presented by a Foojay community manager.

IntelliJ IDEA: Beyond The Basics

IntelliJ IDEA Ultimate is the most powerful IDE for JVM developers in the market by now. It has support for various JVM frameworks, complex refactorings, Integration with VCS, and many more.

Java developers spend a tremendous amount of time in front of their IDEs. Unfortunately, I’ve noticed that developers don’t take advantage of IDEA’s powerful features.

In this article, I’ll talk about some tricks that I use in my day to day job. And show you some best practices that can boost your productivity.

A Compendium of 2021 Java & OpenJDK Predictions

Now that 2021 is well underway, many prominent Java developers have taken the time to predict what 2021 may bring to the Java universe.

In this post, I arrange these predictions and observations by topic, in essence creating a series of brief panel discussions about each topic area: a sort of mini-Java conference in the form of an article!

Explaining Java Deserialization Vulnerabilities (Part 1)

Java serialization is a mechanism to transform an object into a byte stream. Java deserialization is exactly the other way around and allows us to recreate an object from a byte stream.

Java serialization—and more specifically deserialization in Java—is also known as “the gift that keeps on giving”. This relates to the many security issues and other problems it has produced over the years.

Vert.x Example on the Raspberry Pi with a Virtual Potentiometer

The Raspberry Pi allows us to do a lot of electronic projects without having to wait for ordered components… or even buy them at all… by using virtual components.

Today, I want to show a way to play with a potentiometer. A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.

CI/CD Workflow for Spring Boot Applications on Kubernetes via Skaffold

Developing applications with Kubernetes is not such an easy task and that’s where Skaffold comes into play.

It eases the development and deployment of your applications running on Kubernetes.

It manages the entire workflow and you get instant feedback while developing and deploying your application locally or on a remote Kubernetes cluster.

High Performance Rendering in JavaFX

In this article, we comparatively evaluate four different approaches to render particles in JavaFX in terms of runtime performance.

The approaches are Canvas, PixelBuffer AWT, PixelBuffer CPU and PixelBuffer GPU.

The evaluation suggests the following order of approaches from fastest to slowest:

– PixelBuffer GPU (fastest).
– PixelBuffer CPU.
– PixelBuffer AWT.
– Canvas (slowest).

Hacking Java XML Input via External Entity Injection

Java natively supplies many different options to parse XML. However, all available parsers in Java have XML eXternal Entity (XXE) enabled by default. This makes Java XML libraries particularly vulnerable to XXE injection.

In the video, I explain and demonstrate how an XXE injection attack works by extracting system data that should not be exposed.

I also show you how you can solve this in your Java code in multiple ways.

Preview of January 2021 OpenJDK Update Release

On the Tuesday closest to the 17th day of January, April, July, and October under the normal Oracle Critical Patch Update schedule, a new quarterly OpenJDK update is made available.

For the January 2021 update, set to be released next week, a preview is available from today on the foojay.io, on the frontpage, you’ll see a new button is available providing you access to the preview.

3 Ways to Refactor Your Code in IntelliJ IDEA

In this blog, we’re going to look at 3 ways to refactor your code in IntelliJ IDEA.

Simplifying your code has lots of advantages, including improving readability, tackling technical debt, and managing ever-changing requirements. The three types of refactoring we will look at in this blog are:

– Extracting and Inlining
– Change Signature
– Renaming